Must you have a floor in the shed ?
Could you mount it direct on a cast slab that has an inch raised lip to come up inside the floorless shed . If so consider hiring an electric or petrol mixer .
Heres what I did 30 years ago ( I can't remember what I did yesterday though
)
Mark out the base area & add a few more inches so the base is bigger then the shed .
At each corner & in the middle of each wall dig a square one foot deep hole so that you can fix the shed to the base using li=ong coach screws & 10 mm blue wall plugs .... or if you can afford them six inch long stainless steel anchor bolts that need a chemical fix glue to " weld them into teh dry or damp concrtete .. there is little or no stress on these chemical anchors ...
I fitted a 40 x 20 x 6 mtr high steel shed to the floor using the above manner & 10 mm x 150 long bolts , big [penny washers & nylock bolts . It's been stood there for over 25 years to my knowledge .
Fill the holes with home made concrete using " all in one " aka mixed ballast 6 level small plastic buckets of it to one of cement powder . . the floor itself for such a shed only needs to be 3 " thick . laying down old chain link fence or stock /pig wire can be a very cheap & easy form of reinforcement .
Lay out a sheet of waterproof membrane to stop damp coming through , line the holes as well , lay the reinforcing down , set the sides & peg them bring the excess membrane up & over the edge of the wood frame , don't cut it off just yet . Fill the form and tamp it down with another section of CLS .
carefully knock in square wood pegs so they run along side the frame & use wood screws to screw the frame to the pegs FROM THE OUTSIDE of the frame ( so you can get to them to unscrew them afterwards )
The delivery guys were able to drop the three dumpy bags of all in one right next to th site of the slab & also place th cement powder on a large plastic sheet which I quickly wrapped over & weighted it down on the bags as it had started to rain .
Alison put the !/2 & 3/4 barrow loads of concrete in the frame after I made a ramp in & out for her to get the barrow over the lip without moving the frame .
If you think it is a big job think of the money you will save . You could cast the floor in two sections of 8 x5 so long as you dig a trench where the join will be and push in five lengths of threaded studding 10 x 200 mm in the dividing block. I used 4 inches of styro foam to make a thick a bar made up of several thicknesses , supported by a CLS backing bar fixed to three pegs. I poked five 8 inch lengths of the bar in the foam so the bare end protruded into the area being filled with concrete.
The reason for th one foot square holes ... they are the places where the anchors are going to be set in so need a bit of weight & " meat " to ensure no movement or break out
Costs you can get up to date prices for , I think I've named all th items .
20 x 80 mm square head x 6 mm coach screws to make frame & fix pegs
Pack of 10 x 10 mm bolt size chemical anchor fix glues .....you don't really need the stainless steel or plastic glue holding cups if you are using them in a vertical hole.
( Beware of buying out of date off eBay stuff that looks cheap , often it is no good )
Pack of 10 x 150 x 10 mm stainless steel anchor bolts .
OR ....
Two x 1m , 10 mm stainless studding cut to size , add an extra length if you are going to do a two slab cast .
10 large penny stainless steel flat washers with a 10 mm hole
10 x 10 mm stainless steel nylock nuts put the nuts on the anchors before you put the anchors down the wet chemical filled hole . Only tighten them up about 48 hrs later when the chemical has soaked into the set week to ten days old concrete slab & has fully cured . Doing it earlier will not give such a good chemical bond / fix into the concrete .
The frame timber
75 x 40 ClS four x 8 foot ( 2.4 mtr & two x 16 foot ( 5 mtr )
Cut the frame fixing pegs from the excess ,
Three dumpy bags of mixed ballast
15 bags of cement powder .
Use at 6 ballast to 1 powder by volume bucket measuring, not shovels full or weight
I estimate it will require about 15 x 3/4 brickies barrow loads of concrete to fill the frame .
That sort of sized base took me about five hours work to mix up with 1/2 hr break for lunch & me using a long handled ladies garden spade to load the mixer , cut the sides out of one face of the dumpy bag for easier access to the ballast .
I doubt I'll ever forget it took me 90 of my tiny spades full of ballast per barrel mixed .
I seem to recall it saved us just eleven times the cost of the materials . Don't recall having to buy any extra stuff either
Though I did own the mixer Any excess material could be used to make a slab at the shed door at a later date .
Topic: Shed base (Read 2693 times)
